"Bachelorette" Emily Maynard Cheating Story -- Who Do You Believe?

"The Bachelorette" star Emily Maynard vehemently denied reports she was caught cheating on Jef Holm -- but today, someone in Jef's family is backing up the story.

Though the two are very much together now (just check out the photos above of the happy couple on Tuesday above), Us Weekly says they had a huge fight while vacationing with Jef's family earlier this month.

The report said Jef also found "explicit text messages" sent to and from another man on Emily's phone.

"It's one hundred percent not true," Maynard said to PEOPLE of the story, with Jef adding "It's just bogus a 'source' would [say] we were fighting. None of that is true."

But now Jef's brother is telling a very different story.

"I can tell you that it's all 100% true," Mike Holm tells Us Weekly today. "I was there and I heard the fight and watched the whole thing go down, Emily leaving and everything. I love my brother very much and, like the rest of our family, I just want him to be happy."

From the look of the latest pics above, he is ...with Emily. But do you think the fight really happened? Sound off below.

UPDATE: Jef just tweeted about his brother, writing "It's crazy what people will do, even family members, to see their name in a magazine."